Making ceramic articles



Jan. 10, 1939. R. E. GOULD 2,143,003

MAKING CERAMIC ARTICLES Filed Aug. 9, 1937 FIG. I FIG. 3 FIG. 5

2 4 6 Emmy g FIG. 2 FIG. 4 FIG. 6

FIG. 7 FIG. 9

a v v i FIG. 8 FIG. IO

FIG. II FIG. l2

Robem E. Gould INVENTQR av MAM ATTORNEY Patented Jan. 10, 1939 PATENT. OFFICE Mannie CERAMIC .m'rrcms' Robert a. Gould, Norris, Tenn.

Application August 9, 1931, Serial No. 150,144

6 Claims. (01. 25-156) (Granted under the amended April 30, 1928; 3'10 0.

The invention herein described may be manufactured and used by or for the Government for me of any royalty thereon.

ceramic articles, particularly flatware Belieek, and bone china,

governmental purposes without the payment process of making of china This invention relates to a or porcelain body.

One of the objects of this invention is to produce fired ceramic flatware articles with a minimum of deformation in' those zonesof jstress where either the influence of gravity or internal strain causes such undesirable effects. Another object of this invention is to'provide a method for forming ceramic articles rapidly and with a minimum of expense in order that deformation be practically eliminated in subsequent firing. Still another object of this invention is to provide a method for making ceramic flatware articles with a minimum of deformation of the finished article where the shape of the edge of the article is other than circular. Other objects of this invention include the provision of a method for rapid and automatic mechanism formation of articles, 'a method for forming very thin ceramic articles and a method for firing a stack of a plurality of formed ceramic articles with a resulting minimum deformation in the finished articles.

Ceramic flatware is easily formed by jiggering or casting from semi-vitreous or hotel china type bodies but such articles present a difficult problem in delivering the ware straight from the firing kiln. Deformation in fired ceramic articles is caused for the most part by internal strains arising from one or more of the following sources: characteristics of the plastic body from which-the articles are formed, method of forming the ceramic. articles,-and skill or lack of skill exhibited during the forming operation. These internal strains are subsequently evidenced, first, durin the drying of the formed ceramic articles, and secondly, during the firing of the dried formed ceramic articles. Kiln placing methods, such as used in the manufacture of true porcelain,

formed ceramic product but the kiln capacities are severely restricted. .This latter objectionable feature might be overcome provided a kiln fill equal to or better than that obtained using semi-vitreous orhotel china type ware could be employed wherein sand, calcined kaolin and mixtures ofcalcined kaolin and alumina are filled in between the plates.

' This has not, however, been hitherto attained particularly in connection with the use of porcelain type ceramic ware, In the hitherto known separated from a similar zone in result in a satisfactory the center of the obverse side of another methods of firing, the processes commonly used do .not provide any way for bracing-the centers of the ware, which have a tendency to drop if .the ware is thin; the processes used do not make forbracing carry an excessive amount of dust;

the materials used for bracing considerably effect the translucency of the ware and have a tendency to pack and fuse into the ware; and 15 the materials used for bracing have to be re-' ground or otherwise treated before reuse. I have discovered a process of making ceramic ware which provides for firing a plurality of the formed ceramic articles entirely separated 20 from each other. The zone of greatest potential deformation of a formed ceramic article, namely, at or adjacent to the external edge or rim, is

an adjacent, article by a formed ceramic ring-like element 25 made of plastic clay of the same body or body of the same'characteristics as that from which the ceramic articles are formed, each element of a shape such that a portion of the element is complementary to the reverse side of an article 3 adjacent to the rim, such that a portion of it extends beyond the rim of an article and of a thickness corresponding to the distance between the obverse sides of the rims of twoadlacent articles as subsequently assembled. Another zone of potential deformation of a formed ceramic article, namely, the center portion of the article inside its foot or equivalent position, is separated from a similar zone inan adjacent article by a formed ceramic disc-like element made of plastic 40 clay of the same body or body of the same characteristics as that from which the ceramic articles are formed, each element of a shape such that its thickness corresponds to the distance between the center of the reverse side of an article and article below and adjacent to the first article as subsequently assembled.

The generic invention and another specific adaptation are described and claimed in my 00- 5o pending application Ser'. No. 158,143, filed August I 9, 1937, and still another specific adaptation is described and claimed inmy copending application Ser. No. 15,8,145,\filed August 9, 1937.

' v In the accompanyt drawing, whichforms a u part of the specification, and wherein reference symbols refer to like parts wherever they occur,

Fig. 1 is a plan view of the reverse side of one of the formedceramic articles,

Fig.2 is a vertical section of Fig. 1,

,Fig. 3 is a-plan view of a formed ceramic disclike element used subsequently in the assembling of the articles for firing,

Fig. 4 is a vertical sectional view of Fig. 3, Fig. 5 is a plan view of the obverse side of a formed ceramic ring-like element used subsequently in the assembling of the articles for firing,

Fig. 6 is a vertical sectional view of Fig. 5, Fig. 7 is a plan view of the obverse side of a green ceramic setter, Fig. 8 is a vertical sectional view of Fig. 7, Fig. 9 is a plan view of a fired refractory setter, Fig. 10 is a vertical sectional view of Fig. 9, Fig. 11 is a vertical sectional view of a plurality of formed ceramic articles shown in Fig. 1 and Fig. 2 (with only two such articles shown for purposes of illustration) assembled on. a green ceramic setter as shown in Fig. 7 and Fig. 8 separated by a disc like element as shown in Fig. 3

and Fig. 4 and a ring-like element as shown in- Fig. 5 and Fig 6 resting on a fired refractory setter as shown in Fig. 9 and Fig. 10 and ready for firing to the desired maturity, and

Fig. 12 Ba vertical sectional view of the assembly shown in 11 after firing to the desired maturity.

In Fig. 1 and Fig. 2, a formed ceramic article 2 is shown prepared for firing.

In Fig. 3 and Fig. 4, a formed ceramic disc-like element 4, of the same material or with the same physical properties as the material from which the article 2, is prepared i shown.

In Fig. 5 and Fig. 6, a zermed ceramic ringlike element 6, of the same material or material of the same physical characteristics as article 2, is shown.

In Fig. '7 and Fig. 8, a green ceramic setter 8, of the same material or material of the same physical characteristics as article 2, has at least a part of its obverse side identical in shape to the obverse side of the formed ceramic article 2.

In Fig. 9 and Fig. 10,- a fired true shaped refractory setter II, has the observe side complementzry'to the reverse side of the green ceramic set- In Fig. 11, a'plurality of leather hard ceramic articles 2, with ceramic disc-like elements 4, as shown in Fig. 4 and ceramic ring-like elements 6, as shown in Fig. 6 are assembled on a green ceramic setter 8, as shown in Fig. 8, resting on a true shaped fired refractory setter III, as shown in Fig. 10 with all the zones of contact between the ceramic articles 2, the disc-like elements 4, and

the ring-like elements 6, separated by dustingwith a finely divided refractory l2, which is neutral to the body of the ceramic article at the temperature of subsequent firing.

In Fig. 12, the fired ceramic article It, with the fired disc-like element [6, and the fired ring-like isfactory operation of my invention, the actual limits of which cannot be established except by a detailed study of each set of raw materials and the intermediate and finished products involved.

The ceramic flatware articles may be formed by conventional methods, such as jiggering or casting. This particular invention relates specifically through the center line of the foot and thirdly,

and by far the most important, the exterior rim of the article where deformation is caused by gravity on the one hand and marked unevenness by the effect of internal strains in the body of the formed ware on the other hand.

I have discovered that practically all deformation of ceramic flatware articles during firing can be eliminated by firing stacks of flatware articles with their respective zones of most serious deformation, except the foot, separated by unfired ceramic elements made of plastic clay of substantially the same characteristics as the body of the articles. Since the zone of most serious deformation lies at the rim of the formed ceramic article,-

the ceramic ring-like element. used in this zone is of the most importance. The individual ceramic ring-like elements may be formed in any suitable manner, such as by jiggering or casting,

but, in any event, should have substantially the same physical properties as the ceramic articles which they are to separate. The individual ceramic ring-like element used to separate the formed ceramic articles are of a shape such that a portion of the element'is complementary to the I Since the other zone of deformation, namely,

that of the center of the article, ordinarily requires another ceramic element to be placed beneath it so as to separate it from the article immediately below it, it is necessary to supply a ceramic element for this purpose. This second ceramic element may be of any suitable shape, preferably in the form of a disc. The ceramic disc-like. element used to separate the formed ceramic articles, if unfired, is of a shape such that its thickness corresponds to the distance between the center of the reverse side of an article and the center of the" obverse side of another article below and adjacent to the first article as subsequently assembled. The ceramic disc-like element used to separate the formed ceramic articles, if fired, is of a shape such that its thickness corresponds to the distance between the center of the reverse side of an article and the center of the obverse side of another article below and adjacent to the first article after firing. It-is necessary to separate all of the ceramic elements, whether they be articles proper or separating elements, from each other by the use of a finely divided refractory which is substantially neutral to the body from which these elements are made at the temperature of subsequent firing. A finely divided alumina, such as finer than 150 mesh, has been found suitable for this purpose.

It has been found desirable to use a formed unflred'setter which has at least a portion of its obverse side identical in shape to the obverse side of the formed unfired ceramic article. This is preferable in order that an assembly of unflred that the primary shrinkage has already taken place and any subsequent slight flexing may take place without undue distortion.

A true shaped fired refractory setter with its obverse side complementary to the reverse side of the unfired setter is provided as a base for assembling a stack of unfired elements.

A stack of the unfired elements is prepared for drying and firing by placing a fresh leather hard unfired setter on a true shaped fired refractory setter and by building up alternately on the fresh leather settera ceramic ring-like separating element, a ceramic disc-like separating element and one of the formed ceramic articles, with the respective unfired articles, rings, discs and setter separated by a finely divided refractory which is neutral to the body of the ceramic article at the temperature of subsequent firing, with the respective rings and disc in substantial accurate vertical alignment and with the bottom article in accurate horizontal and vertical.

alignment with the obverse side of the fresh setter. It has been found possible to assemble much more than the usual number of ceramic articles in this'm'anner for firing. Ordinarily the number may range from 18 to 36 articles, depending upon the size and shape of the article.

The assembly is fired under conditions of tem-.

perature, time and atmosphere to obtain a desired maturity. During the firing, there is an appreciable shrinkage of all the original unfi'red elements of the assembly, with this shrinkage varying considerably with the plastic material from which the articles are formed. It may, for example, vary from 8 to 18%.

After firing, the assembly is dismantled and the finely divided refractory adhering to the fired ceramic articles is removed from the articles.

Certain terms used throughout the description and claims are understood to have the following meaning: obverse side refers to the top of the article or element as assembled for firing regardless of how the article or element is actually formed andlikewise reverse side refers to the bottom of the article or element as assembled for firing regardlessof how the article or element ,is actually formed. a

It will be seen, therefore, that this invention actually may be carried out by the modification of certain details without departing from its spirit 01 scope.

I claim:- v 1. In a process of making a plurality of ceramic flatware articles, which have substantially identical dimensions, the step which comprises, superposing for subsequent firing a plurality of ceramic elements comprising a plurality of leather hard ceramic articles, preformed from plastic material, and a leather hard ceramic separating element, subjacent to each ceramic article, preformed from the plastic material from which the ceramic articles are formed and so shaped that a portion of the element is complementary to that portion of the reverse of a superposed article adjacent to its rim, that a portion of the element extends beyond the rim of the article and that the thickness of that portion of the element extending beyond the article corresponds to the maximum thickness of the articles. I

2. In a process of making a plurality of ceramic flatware articles, which have substantially identical dimensions, the step which comprises, superposing for subsequent firing a plurality of ceramic elements comprising a plurality of leather hard ceramic articles, preformed from plastic material, and a leather hard ceramic separating element, subjacent to each ceramic article, preformed from a plastic material which has the same physical properties as the plastic material from which the ceramic articles are formed and so shaped that a portion of the element is complementary to that portion of the reverse of a superposed article adjacent to its rim, that a portion of the element extends beyond the rim of the article and that the thickness of that portion of the element extending beyond the rim of the article corresponds to the maximum thickness'of the articles.

3. In a process of making a plurality of ceramic flatware articles, which have substantiallyidentical dimensions, the step which comprises, superposing for subsequent firing a plurality of ceramic elements comprising a plurality of leather hard ceramic articles, preformed from plastic material, a leather hard ceramic separating elementysubjacent to each ceramic article, preformed from the plastic material from which the ceramic articles are formed and so shaped that a portion of the element is complementary to that portion of the reverse of a superposed article adjacent to its rim, that a portion of the element extends beyond the rim of the article and that the thickness of that portion of the elerim of the ment extending beyond the rim of the article corresponds to, the maximum thickness of the articles, a leather hard setter, preformed from the plastic material from which the ceramic articles are formed with at least a part 'of the obverse of thesetter substantially identical to'the obverse of the leather hard ceramic articles, and a fired refractory setter, with the obverse of the fired setter complementary to the reverse of the leather hard setter,

4. In a process of making a plurality of ceramic flatware articles, which have-substantially identical dimensions, the step which comprises superposing for subsequent firing a plurality of ceramic elements comprising a plurality of leather hard ceramic articles, preformed from plastic material, a leather hard ceramic separating element, subjacent to each ceramic article, preformed from a plastic material which has thesame physical properties as the plastic material from which the ceramic articles are formed and from a plastic material which has the same phyk} sical properties as the plastic material front which the ceramic articles are formed, with at least a part of the obverse of the setter substan- I6 tially identical to the obverse of the leather hard ceramic articles, and a fired refractory setter, with the obverse of the fired setter complementary to the reverse of the leather hard setter.

5. In the process according to claim 3, wherein a leather hard separating element is placed sub- .iacent to the .center of each ceramic article with said separating element preformed from the plastic material from which theceramic articles are formed and so shaped that the thickness of the element corresponds to the distance between the center of the obverse of a ceramic article and the center of the reverse of a superposed ceramic article.

ceramic article and the center of the reverse of m a superposed ceramic article.

ROBERT E. GOULD.

Patent No. 2,IL;5,003.

ROBERT E; GOULD.

January 10, 1959 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 25, for the word "mechanism" reazkmechanical; page 2 second column, line 10, for "flateware" read flatware ;1 page i frirst column, line 51, for "disc" read discs; and that the said L tt Patent shouldbe read with this correction therein that the same may conform to the record of' the case in the Patent Office.

Signed and sealed this 2lst'day of February, A. D. 1959.

(Seal) Henry Van Arsdale Acting Commissioner of Patents. 

